In subsea operations such as oil and gas exploration it is common to utilize a stab containing a flowline for charging and discharging of liquids within a manifold. Various engagement mechanisms are used in connecting and maintaining the connection between the stab and the manifold. Seals are placed on the stab and are used to maintain the connection between the stab and the manifold. The seals are positioned within the stab in such a manner that the hydrostatic pressure maintained in the lower end of the stab exerts an upward force while the hydrostatic pressure at the upper end of the stab exerts an equal downward force. A lateral outlet port in which fluids can be discharged is provided between the seals. The offsetting forces create a stab that remains as positioned within the manifold.
In a conventional stab assembly the seals consist of O-rings placed on the stab. Once the stab is submerged, these seals facilitate the connection of the stab to the manifold. The disadvantage with the O-ring seal design and other commonly used seals is that during insertion of the stab into the manifold the seals may become damaged, which would result in receptacle leakage.
It is therefore an object of the present invention to provide a unique sealing arrangement which allows dependable sealing at much higher pressures, i.e. greater than 15,000 pounds per square inch, than the seals used in hydraulic stabs.